CD19 is expressed on normal B cells and by cells and tissues of various diseases and conditions, including most B cell malignancies. Most patients with B cell malignancies are not cured by available therapies, including therapies targeting CD19 and/or other B cell markers. Various CD19-binding molecules, including anti-CD19 antibodies, and chimeric antigen receptors containing anti-CD19 antibody portions, and cells expressing such chimeric receptors, are available. Improved CD19-binding molecules and engineered CD19-targeting cells are needed. For example, there is a need for molecules and cells with reduced immunogenicity and/or human antibodies, including antibody fragments that specifically bind to CD19 and chimeric receptors expressing such human antibodies for use in adoptive cell therapy. Provided are embodiments that meet such needs.